Infrastructure projects worth $87 billion being rolled out across New South Wales over the next four years are being carried out with no safeguards to protect subcontractors' businesses, a Government commissioner has revealed.

New South Wales small business commissioner Robyn Hobbs has hit out at the building and construction sector, saying "unconscionable" practices remain rife.

"I rail against this, when contractors use the money due to be paid to subcontractors for their own operating expenses," Ms Hobbs said.

York Civil is the latest company working on the Pacific Highway upgrade between Woolgoolga and Ballina to go into voluntary administration, leaving some subcontractors out of pocket.

One subcontractor who spoke with the ABC said he was now owed $9,000 by York Civil and its joint venture partner, Spanish company OHL.

"I've already had another [mining] contractor go broke on me this year for $35,000, so little people like me just can't keep taking hits like that," the subcontractor said.

"I should have seen the signs but they kept assuring me I'd get paid the next week.

"It's just a stalling tactic from these guys so they get all their ducks in a row and then put it into administration. Once it's in administration you are basically screwed. There's nothing you can do."

He said it should not be up to subbies to engage lawyers to chase their own money.

"RMS [Roads and Maritime Services] should be stepping up to the plate and making sure these people honour their commitments.

"They shouldn't be given a massive contract like that if they can't pay their bloody bills, and they shouldn't be allowed to just wind them up to escape that."

Culture of bullying and harassment

Fellow north coast subcontractor Simon Davis said a culture of bullying and harassment existed among lead contractors on the Pacific Highway upgrade.

Mr Davis said he had been underpaid $300,000 on a contract, and when he raised the issues with management, his company was given three safety breaches and kicked off the site for five months.

He said as a result, he had been forced to lay off staff and put his 20-year-business into voluntary liquidation.

"It has destroyed my business. I've run out of cash. I'm going to have to go into voluntary liquidation," he said.

"For me it's absolutely heartbreaking because I've built my company up 20 years ago to be the best and I've been chewed up and spat out."

Mr Davis said he told his story at a Ballina Shire Council meeting in the hope other subcontractors would be spared.

"Mentally, it's done some damage," he said.

"Three weeks ago I had to let go of all my staff. I've had to go home to my wife and children and tell them I can't provide for them anymore."

Trust system considered to protect subcontractors

Following the collapse of Ostwald Brothers last year, the State Government was forced to reimburse 23 subcontractors owed more than $7 million.

The Government is now looking to reform the Building and Construction Security of Payment Act and is seeking feedback on the idea of a cascading statutory trust system.

Minister for Better Regulation Matt Keane said previous reviews of the act showed a trust system was the best way to protect subcontractors down the contractual chain from insolvency or misuse of funds further up the chain.

"Why should a subcontractor supply a contractor with interest-free working capital? And that's the principle here," he said.

Mr Keane said 20 per cent of all company insolvencies in New South Wales over the past 10 years had been in the building sector.

He said while the review was still under discussion and would ultimately require legislative reform, its success would depend on the Office of Fair Trading's ability to enforce the trust system.

Ms Hobbs has welcomed the review, but said industry reform was being opposed by some of the big players.